Abstract
The relationship between satellite-derived low-level cloud motion, surface wind and geostrophic wind vectors is examined using GATE data. In the trades, surface wind speeds can be derived from cloud motion vectors by the linear relation: V = 0.62 V s + 1.9 m s−1 with a mean scatter of ±1.3 m s−1. The correlation coefficient between surface and satellite wind speed is 0.25. Considering baroclinicity, i.e., the influence of the thermal wind, the correlation coefficient does not increase, because of the uncertainty of the thermal wind vectors. The ratios of surface to geostrophic wind speed and surface to satellite wind speed are 0.7 and 0.8, respectively, with a statistical uncertainty of ±0.3. Calculations of the ratio of surface to geostrophic wind speed on the basis of the resistance law yield V/V g = 0.8 ± 0.2, in agreement with experimental results. The mean angle difference between the surface and the satellite wind vectors amounts to α ∼- 18 °, taking into account baroclinicity. This value is in good agreement with the mean ageostrophic angle α ∼- 25 °.
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Blackadar, A. K. and Tennekes, H.: 1968, ‘Asymptotic Similarity in Neutral Barotropic Planetary Boundary Layer’, J. Atm. Sci., 25, 1015–1020.
Clark, R. H. and Hess, G. D.: 1975, ‘On the Relation Between Surface Wind and Pressure Gradient, Especially in Lower Latitudes’, Boundary-Layer Meteorol., 9, 325–339.
Fielder, F.: 1972, ‘The Effect of the Baroclinicity on the Resistance Law in a Diabatic Ekman Layer’, Beitr. Phys. Atm., 45, 164–173.
Godshall, F. A., Seguin, W. S., and Sabol, P.: 1976, ‘GATE Convection Subprogram Data; Analysis of Ship Surface Meteorological Data Obtained During GATE Intercomparison Periods’, NOAA Technical Report EDS 17, Washington.
Halpern, D.: 1978, ‘Comparison of Low-Level Cloud Motion Vectors and Moored Buoy Winds’, J. App. Meteorol., 17, 1866–1871.
Hasler, A. F., Shenk, W. E., and Skillman, W. C.: 1977, ‘Wind Estimates from Cloud Motions: Results from Phases I, II and III of an in situ Aircraft Verification Experiment’, J. App. Meteorol., 16, 812–815.
Hasse, L.: 1974, ‘On the Surface to Geostrophic Wind Relationship at Sea and the Stability Dependence of the Resistance Law’, Beitr. Phys. Atm., 47, 164–173.
Hasse, L., Grünewald, M., Wucknitz, J., Dunckel, M., and Schriever, D.: 1978, ‘Profile Derived Turbulent Fluxes in the Surface Layer Under Disturbed and Undisturbed Conditions During GATE’, Meteor-Forschungsergebnisse, Reihe B, No. 13.
Hubert, L. F. and Whithney, L. F. Jr.: 1971, ‘Wind Estimates from Geostationary-Satellite Pictures’, Monthly Weather Rev., 99, 665–672.
Krishnamurti, T. N., van Dum, G., Pan, H.-L., Hughes, L., Pasch, R. J., and McGray, R.: 1976a, ‘Cloud Motion Vectors for GATE’, Report No 76-1, Department of Meteorology, Florida State University.
Krishnamurti, T. N., Wong, V., Pan, H.-L., van Dum, G., and McClellan, D.: 1976b, ‘Sea Surface Temperature for GATE’, Report No 76-3, Department of Meteorology, Florida State University.
Roll, H. U.: 1965, Physics of the Marine Atmosphere, Academic Press, New York, 465pp.
Suchman, D. and Martin, D. W.: 1976, ‘Wind Sets from SMS Images: An Assessment of Quality for GATE’, J. App. Meteorol. 15, 1265–1278.
U.S. Navy, 1958: Marine Climatic Atlas of the World, Vol. IV, ‘South Atlantic Ocean’, Direction of the Chief of Naval Operations.
Wolf, H.: 1968, Ausgleichsrechnung nach der Methode der kleinsten Quadrate, Ferd. Dümmlers Verlag, Bonn, 417–422.
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Zank, S. Sea surface winds derived from cloud motion vectors over the tropical Atlantic. Boundary-Layer Meteorol 19, 223–233 (1980). https://doi.org/10.1007/BF00117221
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DOI: https://doi.org/10.1007/BF00117221